Boring head



Dec. 21, 1948. w. PENN-GASKELL HALL 2,457,040

BORING HEAD Filed Jan. 1o. 1945 s sheets-sheet 1 KKK 'i r: Sima.

W. PENN-GASKELL HALL Dec. 2l, 1948.

BORING HEAD 3 Sheets-Sheet 2 Filed Jan. 10, 1945 Dec. 2l, 1948. w. PENN-GAsKr-:LL HALL 2,457,040

BORING HEAD Filed Jan. 10, 1945 5 Sheets-Sheet 3 Patented Dec. 21, 1948 UNITED STATESI PATENT OFFICE BORING HEAD William Penn-Gaskell Hall, Berwyn, Pa.

Application January 10, 1945 Serial No. 572,121

(Cl. T7-57) 9 Claims. l

As my invention is of particular utility in connection with horizontal boring mills although equally adapted for use with boring mills of other types, I shall describe it more especially with reference to such a mill, which, in general, comprises a horizontally extending rotatable, longitudinally movable bar from which the cutter extends radially and which is journaled in heavy pedestals rising from the base of the machine, together with a work holding support on which the work, for example a cylinder, is mounted between the pedestals with the bar extending substantially centrally through its bore, so that when the cutter is suitably adjusted and the rotating bar fed longitudinally a cut will be taken in the interior of the work, usually beginning at one end thereof and terminating at the other, to form a bore truly central with the axis of the bar.

My invention contemplates the provision of a head or attachment which is seated on the bar and through the medium of which the cutter may be adjusted radially with great facility, rapidity and accuracy in accordance with the diameter of bore to be formed in the work and, additionally, may be fed radially when desired whereby facing or other cuts in planes normal to the axis of the bar may be made. Thus with one setting-up of a work piece it may be bored and also end faced in the mill whereby absolute parallelism between its end faces and the axis of its bore may be attained and the necessity for resetting-up the piece for end facing after boring or vice versa entirely obviated while, in addition, the heavy cutting strains and the need for frequent resharpenings experienced with the conventional full face-width cutting tools now employed for facing cuts are eliminated as well as the diiculties inherent in sharpening and resetting the conventional facing tool to true parallelism.

The principal objects of the invention therefore are the provision of a boring head adapted for use in conjunction with a boring mill or the like which, among other things, facilitates setting the cutter for boring operations with maximum precision and in a minimum of time, which also permits the performance of facing and like operations with maximum precision and convenience through its ability to impart to a cutter progressive movement in a plane normal to the axis of the boring bar, and which may readily be conditioned for taking such cuts.

Other objects, advantages and novel features of design, construction and arrangement comprehended by the invention are hereinafter `more 2 A particularly pointed out or will be apparent t those skilled in the art from the following description of certain embodiments thereof as illustrated in the accompanying drawings in which :v

Fig. 1 is a view of the head in operative asso# Fig. 8 is a fragmentary section on line 8.-8 in Fig. 7; and

Fig. 9 is a perspective view of the brake shoe removed from the assembly.

Fig. 10 is a perspective detail of the clutch key removed from the assembly; f Fig. 11 is a side elevation of a modified fo of the invention; and

Fig. 12 is a fragmentary rear endelevation thereof on a smaller scale.

Like symbols of reference are used in the several flgures to designate the same parts, and the directions in which the various sections are taken are indicated vby the arrows on the section lines.

More particularly that form of the head shown in Figs, 1-9 inclusive comprises a hollow cylindrical body I adapted to snugly seat about a borf ing bar B to which it is operatively secured by two or more radially extending set screws 2 bearing against brass plugs 2 in turn bearing on` the bar, thus preventing scoring of the latter. At one end, for convenience termed the front end, the body isprovided with a transversely extendingr slot Il for reception of a U-shaped slide 5 which is held in the slot by a cap 6 removably secured. to the end of the body by longitudinally extending screws l. The closed end of the slide is countersunk or otherwise suitably arranged for reception of a cutter holder generally designated as 8 which may be of any convenient construction adapted to hold a cutter C rigidly in proper position in the slide. Since theholder may be of any specific type adapted for its intended function detailed description of it would be superfluous although a holder of the form shown in Fig. 2 may vbe satisfactorily employed, and it will ofcourse be understood thatdiierent forms of cutters C are used for boring and for facing, that shown being designed for the former purpose.

Slide 5 embraces bar B and is capable of being moved radially with respect thereto and for effecting this motion the legs of the slide are provided with camming means, desirably angularly disposed lands 8 and grooves Si square in cross section, cooperating With camming means, such as similar landscilarrdgrooves I lfonxtlrersidesrof a cam blockwl2' :(Fig.16) which is interposedrbee" l0 tween the legs of the slide, its upper face being curved out to substantially conform to the curvature of the bar. This cam block is longitudinally.l

slidable in a groove or chamber f3 extending determined rate in respect to the revolution of l. baraBilwithtresultant longitudinal movement of segmenti!! to effect radial movement of the slide body l and cap 6 and is supported onttwio'fspacedfm .airdfecutter'f' rods I4 the ends of which seat inthebarandcap t respectively, these rods being of^relativelytlarge diameter so a-s to adequately sustain the imposed on them by the block and being preferablyhardenedandground.. To excludechips and. ,20 other.foreign.mattenfromigroove L|3 itis coyered .L

by a removablegshieldil 5.1?.-

It y"will Ithusbe. apparent -that,.when vthe 'scam block,ismoyed.longitudinally on. rods ..l 4 .a radial-.ffv movement `Awill beimpartedf toth'e. slide through- 25 the.y.coacting.,sets.ofrlandsaandlgrooves provided;

the angular disposition.. of Qthe'.,.latter..lis `.notn ex-Vw cessive l Consequently.. while .ianyl`y l.angle -greaterff thangzerlo and? less than ,that at which.Y no .rno..,.

tion-.canhefinduced .in the. slide -may.beselected,Vi 30 I prefer for a reason which Willhereafter appear-.. to locate thelandsandlgroovesYat-anrangle :of 26?v For miniparting., longitudinal movement-...to the cam block thereby to induce the radi-alfmovem ment in the islide, tl'1e.front.endtofga;j drivefwbarel 2D is secured, conveniently as shown, to theablockzm. extendedwtherefrom` .re arvvardlyry y and slidablyfr through va bore in body I- andconnectedeat.itswfo' ment Vslidably bottoms in-afrecessfnfformed in 4theAw i bodylandsisfsurrounded by: an.adjusting sleeve 25:: rotatably seating at its front end-insa peripheral groovefziin. the-bodyiandtabuttingat its rea-1zendzs' 1 against a ring 24 bolted torafangeon the.-latter...`

Wherebyrfthe, #sleeve isl capablemof rotation but f.' noti-off: longitudinalsmovement'- withrespectit'o -fthe bodym 'Ifloeslee-veI is internally. threaded and-'segfa-Yu ment 2 I.-.correspondingly externally, threaded eforn?" rotatingfthefsleeve longitudinali-movement :can

be imparted-to .theisegment .ande in-.turn through-ie drive;r bar. ...2 llA .to l.cam vblock .lll-sofasr to moventhe to facilitatinglrapid. and accurateadjustment prefer.- tdmake'thepit'ch of .thfthre'ads on the' sleeve' andl` segment 10'"perfinclrrfwith .the result,l 1 thatrwhen the gro-@verand lands en the @am block 60 and' slide aredis'p'osed 'at the preferredrangle one tionsfeach thus1indieatingl.001"f rrafdiarfnovemen of the'fslidfso 'shabby-turning:thefsleeve manuali tf1" througheany desiredmumber of graduation'sfcut; y

ter @man .ibevmoyedi'infforaout forrfa 4lm'ownfdiswV tarroe `favhelielcn;:its:-fralzlialfssettingicanfbe accomepf plishedrwerqraccurately!tandlrrapidly..toi dispose-:it l f fort-cutting a. boneoffgivendiameteri-fin the; wor-14;@

Itiwillf further beapparent,thatifthelworkande a' thebar are restrainedifromrrelativelongitudinal moyementland. acuttenC ofqpioperiiformfbe-.disf posed in the cutter holder, a facing cut can be slide; in or outradiallydn correspondencentd thea??? directionofrotation .of thelsleeve. ,l .With a..view..

` More particularly a ring 30 having a rearwardlyexterrdirrg flangeis ysecured to the rear end oi lsleeve-252asfrrby bolts 3l, this ring serving among other functions that of a thrust collar, and about its vlflanged...portion Yand extending .rearwardlyJ thereoisdisposed va rotatable clutch collar SZ* provided with-internal,V preferably square threads d 33 thelcolla'rrbeing.considerably wider than the length .oithe flanges. Within .this .collar and norrrflally.V loverlyingT thelfiangeis `.a .key 35 having external-.threads cooperating with those in' the collar and onitsinner periphery la .longitudinally extending. dogl Whichin .transverse section Ydesirably approximates'a gear tooth in shape.

Clutch collar.32.hasnoconnection with any part n savelre-Ayiandmaygtherefore be rotated manu. ally."to;.move ther-latter'. rearwardly .from the porsitionof.Fig..1 tothat-of Fig. or viceversa whe y desireds` Abuttingvtherean endof. .i ;he;f1ange.,onlring- 36 isadriveniringlgear dllprovided Withexternal l teeth in constant imesh with .those -of .a pinion.,

Il! integralWith-for..operatively securedto .a stud .4,2 rotatably.s eatingin thegenerally hollowcylim.. driealaplanetzf spider d3.. mounted and .normallyf` rotatablenon body i. Rearwardly of pinioniM.,

stud; A2. carriesY another` piniong either integral...

Withiorfoperatively'fixed.to it soV that thestud v vandtlzzothqoinionsalvvays turn'as ,a unit, this pin-1 ionz'ddnmeshingwwith an externally toothed ringv gearfi operatively secured .-to bodyfl as by` keysy it eth1-is; both pinions rotate A`when the body and.

bar-B -are'revolv-ingif spiderllt is restrained from rotationa.. While .buteone-fstud andrpinionl are..Y

shown -in-Fig..1, apluralitythereof arenormally` l utilized, pasfindicatedrin.I iig. 4, to more equallyA distribute--thevdrive aboutthetool. I

Rearwardly.yofstud..d2-spider d3 is reduced in diameter- -for reception `of the-brake mechanisms later-describedyandadjacentiits outer end carries; l a spacenring Lllagainstfywhich ,abut a pair-,of

thrust rings s mathe frearmost of ywhich may'de-Y sirably-fotfneoprene or-someother suitable ma; v

terial while a split collar 49 is threaded onto the."

rear.` endroit-the1 body.V to hold ythe partsr in 'proper longitudinally,adjustederelation'after it has been screwedvinwardly forthe properdistance and constricted -by a transversely extendingclamp screw UML.; The neoprene.#washer-is then effective to u exert.'sufficient-1#friction-v :on the r'partsfsto cause spider43-to-rotate with thefbody save whenV the brak-eds :engagedsf v v Thelunctiorrlofftheglatter. is toreleasably holdA spider I3y against rotation with fbody yl when itisdesir-fedfto-feedcutter@ radially,vand while it mayY be of any construction-.suitablerfor, this-purpose in its .preferredembodiment it comprisesa brake bar .5 5 conveniently*j -terminating...at `itsy outer ex. tremityina. knobA 555 adapted itolbe rested against or engaged with any convenientxed part M of the .mill to thereby hold bar 55 against rotative movement in one direction. The bar projects in a generally radial direction from the body of the head and near its end proximate thereto is provided with an integral collar 56 beyond which it is externally threaded for reception in a correspondingly threaded bore in brake ring 51 which surrounds thereduced rear end of spider d3. This brake yring in proximity to the bar is out out to receive .a movable shoe 58 (best shown in Fig. 9) having curved inner faces conforming tothe adjacent -part of the spider provided with -facings 59 of Suitable friction material adapted to grip ythe spider when the shoe is forced against it through operation Iof a collar E0 through which bar 55 extends and whichbears at its inner end against the outer surface `of the shoe. This collar is slidable relatively to bar 55 and may be biased toward the shoe by a spring 6l seating in a counterbore .at the outer end of the collar between thrustwashers 52, the outermost of which abuts the proximate end of abrake-set sleeve 63 surrounding brake bar 55 and having a camming surface .54 at its opposite end cooperative with a pin -55 projecting from the bar, the sleeve being deslrably exteriorly knurled to afford a satisfactory grip. Thus by cooperation of the cam surface and pln when the sleeve is turned in the proper direction, lspring 6I may be `compressed from the position 'shown in Fig. 1 so as to force collar ASi) against shoe 58 to thereby press friction material 59against the spider with sufficient force to prevent it from turning with body l when bar 55 is blocked against machine base M; thereafter by turning the sleeve in the opposite direc` tion the pressure 'on 'the spider can be released Whenever desired to allow it to resume its normal rotation with the body.

It will be observed that when not in use bar 55 with its attached parts may be readily unscrewed from ring 51 and stored in a convenient place. Moreover when bar 55 is removed and screws 2-2 loosened, the head can readily be moved along barB *through the bore in the work or through a series yof such bores without removing it from that bar.

When the head is being used for boring operations the bar is ordinarily removed asv just suggested 'and the clutch collar is turned so as to bring key 35 to the position shown in Fig. 1, that is, adjacent ring v36; then after a cutter C suitable for boring is placed in `the tool holder it .may be adjusted radially when and as required by manual rotation of adjusting sleeve 25.

When, however, the head is to 4be used for a facing or like operation, a suitable facing cutter is inserted in the holder and brake `bar 55 screwedv into ring 51. Clutch collar 32 is then turned manually `in a direction to move key 35 rear wardly and thus enter its dog 36 between the teeth `of drive gear 40, thereby locking the latter to ring 30 and so to adjusting sleeve 25. Bar B of the mill is then set in motion and either before or vafter 'this is done brake-set 'sleeve 53 is rotated so as to apply the brake to restrain spider 43 from rotation with body l. It results under these conditions that gear 45, which is keyed thereto, drives plnions 44, 4I to turn driven gear 40 relatively to the body because of the difference of the number of teeth in the two pinions, and as gear 4'0 operatively locked through key 35 and dog 38 to ring 30 a similar relative rotative mov-ement is 'imparted to adjusting sleeve l25 which thus gradually moves segment -2 I bar 20 and block I2 longitudinally and consequently slide 5 and cutting tool C radially to enable the latter perform the facing cut. Ultimately', of course.- the permissible longitudinal movement of bloc'k l2 'will be reached and if the rotation of bar B; were .not arrested prior thereto serious damage: tothe head might occur if the braking mechanism. whenever it is engaged were effective to positively hold spider 53 against turning. But since itis4 effective to hold the spider only up to the point'A at which the friction that it exerts thereonis. exceeded, when block I2 reaches the end of its: travel or in case of an excessive overload beingthrown on the cutter at any time such as by an extremely hard spot in the metal, the brake willl` slip and permit the spider to turn, thus terminat-f ing further longitudinal movement of block I2` and radial movement of the slide and so relieving: the parts from excessive strain.

In the preferred construction the ratio of the gear train through which the revolution of 'adjusting sleeve "25 is induced when facing cuts or rthe like are being taken is 10: 1 and the threads.

on the sleeve l0 to the inch whereby ten revolutions of 'boring bar B produce one revolution=of adjusting sleeve 25, thus advancingsegment 2|:

the bar, ibut of course the head may be constructed to "feed theslide and cutter radially for a greater or lesser distan-ce during each of its revolutions! Mention has heretofore been made of the Way in which the position of the cutter and slide are normally adjusted when taking boring cuts, that is, by manual revolution cf adjusting sleeve 2-5,I but in case lan extremely fine adjustment is de-` sired it can be readily obtained by turning -the'- clutch collar so as to engage key 35 with ring gear :i0 whereby to bring the planetary transmission into play, and then manually turning spider/t3` while the brake is in off position; under thesecondi-ti'ons each revolution -of the spider will move the cutter and slide radially .005" when the4 head is yconstructed in accordance with the pre'- ferred practice, 'thus affording in effect a Vernier'y or micrometer adjustment.

When the head is employed in making facing:-

cuts or the like there is, of course, a heavy thrust A boring head constructed in accordance with my invention is capable 4of forming a bore of any: diameter between one whose radius is slightly" greater than the radius of the head itself and one whose `radius is `determined by the maximum extent which the cutter and slide can be moved radially outward, and, preferably, the head is de-l signed to out a minimum bore slightly more than twice the diameter of the boring bar `B being-v used; thus with a 3 bar the smallest bore which can be 'formed is slightly greater than 6" while' the maximum would approximate 8" to 10" -in diameter. Moreover i'f the bore in the body of the hea-d is of greater internal diameter than thel bar -of the mill which is to be employed, abushing can be readily inserted in the body to adaptit mer-cto.

In Figs. 1l and 1-'2 is shown a boring head of modified construction which, "because *of itsslm p'licity, 'low cost of manufacture and smallfnumber of par-ts, may Isometimes be preferred 'to the@v head hitherto described as it is equally effective to perform the various operations of which the latter is capable. In this head they design and arrangement of the body, slide, cam block and its actuating means including the adjusting sleeve are, in general, similar to the corresponding parts hitherto illustrated and described so that further reference thereto is unnecessary so long'as it is borne in mind that rotation of the adjusting sleeve is effective through these various parts and i associated mechanisms to cause radial movement of the'slide. f

Somewhat differ-ent means, however, are provided ior rotating the sleeve relatively to the body and boring bar B when it is desired to feed the slide mechanically, and .reference will now be made to one embodiment thereof as shown in said gures. Thus proximate the rear end of sleeve 25a a collar 'I5 is xed to the body la in any con- Y venient way so as to inhibit longitudinal movement of the sleeve relatively to the body and, rearwardly of this collar, a driving gear 'I6 surrounds the body and is keyed thereto so as to rotate therewith. Behind this gear is disposed a bearing ring 1l' which is freely rotatable on `the body and a split collar 18 threaded onto the other convenient fixed portion of the mill to thereby prevent rotation of the bar in one direction.

This bar supports a stud 83 which is preferably threaded through it and locked in place by one or more nuts 84, the stud extending parallel to the axis of the body of the head. Adja" cent the bracket a pinion 85 is rotatably mounted on the stud in meshing engagement with gear 16 and, remote from the bracket, another pinion 86 is also rotatably mounted on the stud to mesh with gear teeth 8l formedl in the peripheral surface of sleeve 25a, proximate its rear end, the pinions being respectively provided with oppositely directed cylindrical offsets 85', 86 having ratchet teeth 88 on their extremities adapted to mesh with each other. The outer end of the stud is enlarged to form a head SU and between it and pinion 86 is disposed a coil spring 9| which constantly biases that pinion toward pinion 85 and maintains the ratchet teeth on the offsets in engagement so that the pinions normally rotate as a unit.

The ratio of the train consisting of driving gear 16, pinions B5, 86 and gear 81 on sleeve 25a is such that. when in operation the sleeve revolves more slowly than the boring bar B, and is preferably so determined that the sleeve makes 9 revolutions for each 10 revolutions of the boring bar, that is, one Icomplete revolution relatively to the bar to each 10 revolutions of the latter, and so through the cam block l2 and associated mechanisms eiects a predetermined radial progression of the tool slideas long as the latter is capable of moving, but of course the particular ratio employed is a matter of choice.

YOn attainment of the limit of this movement, however, or `should the tool encounter an ex- 25a in condition for manual rotation to effectA radial adjustment of the tool to conform with. the diameter of the desired bore in the work..

tremely hard spot'in the metal suflicient to vim-l` pose an excessive load on the mechanism,thes ratchet teeth between the pinions instead of' maintaining their normal `interiitting engage-7 ment under the bias of spring 9| ride over each-f other against the compression of the spring and so relieve the pinion and sleeve fromfthe positive: drive which would be imparted if the two pinions i were rigidly connected whereby damage to thei various parts which might otherwise occur is defi-1':

nitely prevented.

It will be obvious that when the head` is 'tof be used solely for forming cylindrical bores inthe i work or for other operations `not requiringva1 radial feed of the tool, the bracket 8l carrying the, stud, pinions and bar 82 can be readily removed@ and temporarily laid aside, thus leaving sleeve It will now be apparent that my invention provides not only a boring head which, when associated with a boring bar, enables adjustment ofi the cutter for boring cuts with maximum con-- venience and accuracy but also permits the taking of. facing and like cuts when desired through its ability to imparta radial feed to the cutter inv a plane normal to the axis of the boringbar.; It will further be apparent that through the medium of the boring head of my invention itis possible to form a taper bore in. the work by. feeding the cutter longitudinally and radially at the same time, the degree of taper being determined by the ratio between the .movements of.

the cutter in the two directions. This ratio is of course controlled by thev number 4of turns made.

by and longitudinal feed of boring bar B foreach turn of the adjusting sleeve so that by vchanging the ratio of the gear train or other -means lby which the sleeve is driven bores of differentaper can be formed.

Moreover while I have herein described andy illustrated with considerable particularitycertain embodiments of the invention I do not.'

thereby desire or intend to restrict or confine myself thereto as vnurnerous changes may be.

made in the design, construction and arrangement of the instrumentalities employed andintheir method of assemblyv without departingfrom the spirit and scope vof the invention as defined in thefappended claims.

Having thus described my invention', Iv claim; and desire to protect by Letters Patent of the United States:

1. A self-contained boring head adapted to be slid longitudinally over the end of and ,along va` boring bar to a predetermined position thereon and comprising a hollow generally cylindrical body affording an uninterrupted passage for re'-" ceiving the bar, means operable to removably secure the body to the bar in said positions a slide movable radially of the body having spaced legs extending on opposite sides ofthe bar when. the head is seated thereon, cutter holding meansy adjacent one end of the slide, camming means on the inner faces of the legsof the.slide, a. cam block housed in the body and slidable lon.gi

tudinally thereof having camming means c'o-V operative with those on the slide, an internallyv threaded sleeve rotatably mounted on the body;

block longitudinally and through the interaction of the respective camming means on the block and slide to move the latter radially of the body.

2. A self-contained boring head adapted to be slid longitudinally over the end of and along a boring bar to a predetermined position thereon and comprising a hollow generally cylindrical body affording an uninterrupted passage for receiving the bar, means operable to removably l secure the body to the bar in said position, ai

U-shaped slide extending transversely of and into the body -with its legs on opposite sides of the bar when the head isseated thereon, cutter holding means adjacent the closed end of the slide, inclined lands and grooves on said legs, block slidable axially of the body having lands and grooves cooperating with -those on the slide, an internally threaded sleeve rotatable about the body, a correspondingly threaded element cooperative therewith for longitudinal movement; in the body upon rotation of the sleeve, and means connecting said element and said block whereby rotation of the sleeve is operative through the coactlon ol` the respective sets of lands and grooves to move the slide radially ofi the body.

3. A boring head of the class described comprising a hollow cylindrical body adapted to-surround and for securement upon a boring bar, a slide movable radially of the body adjacent one; end thereof, cutter' holding means, and camming means carried by the slide, a block slidable longitudinally of the body having camming means cooperative with those on the slide, a sleevev rotatable about the body, means cooperar-itive with the'sleeve for translating the block on rotation of the sleeve to thereby move the slide through coaction oi said camming means, and means for automatically rotating the sleeve relatively to the body when the bar is rotating' to thereby move the slide comprising a gear fixed to the body, a spider normally rotatable on the body, coaxial pinions of different diameter carried by and together rotatable relatively to the spider, one of said pinions beingy driven by said gear, a second gear normally rotatable about the body and meshing with the other pinion, disengageableA clutch means connecting the last mentioned gear with the sleeve, and brakemechanism operable to releasably hold the spider vagainst rotation with the body whereby to cause "the rst mentioned gear todrive one of said pinions at a rate determined by the rate of revolution of the body and boring bar and the other, pinion and hence the last mentioned gear and'y the sleeve at a different rate with respect thereto.

4. A boring head of the class describedcomprising a hollow cylindrical body adapted to surround and for securement upon a boring bar, a slide movable radially of the body adjacent one end thereof, cutter holding means and camming means carried by the slide, a block slidable longitudinally of the body having camming means cooperative with those on the slide, a sleeve rotatable about the body, means cooperative with the sleeve for translating the block on rotation of the sleeve to thereby move the slide through coaction of said camming means, and means for automatically rotating the sleeve relatively to the body when the bar is rotating to thereby progressively move the slide comprising a spider normally rotatable on the body, a pair of coaxial pinions carried by and rotatable as a unit relatively to the spider, one of said pinions having a fewer number of teeth than the other, a gear spect to the body.

`fixed to the body meshing-` writh one of said pinions, a gear rotatable relatively to the body meshing with the other pinion, clutch means disengageably connecting said gear vwith the sleeve, and brake mechanism operable to releasably hold the spider against rotation with the body whereby when the clutch means are engaged the last mentioned gear isdrivenby the pinion meshing therewith at a dierent rate from -that at which the body is being. turned thereby tov cause the sleeve to rotate With re- 5.- A-boring head of the class described comprising a hollow cylindrical body adapted to surround -and =for securement upon a boring bar, a slide movablev radially of the body adjacent `one end thereof, cutter holding means and camming means carried-by the slide, a block slidable longitudinallylof the body having -camming means cooperative with those on the slide, a sleeve rotatable about the body, means cooperative with the sleeve for translating the block on rotation of the sleeve to thereby move the slide through co'action of said camming means, and means for vautomatically rotating the sleeve relatively to the body when the bar is rotating to thereby progressively move the slide comprising a spider normally rotatable on the body, a pair of coaxial pinions carried by and rotatable as a unit relatively to the spider, one of said pinions having a fewer number of teeth than the other, a gear xed to the body meshing with one of said lpinions; a gear rotatable relatively to the body meshing with the other pinion, clutch means disengageably connecting said gear with the sleeve and comprising aninternally threaded clutch collar rotatable about the body, an externally threaded key cooperative therewith for longitudinal movement upon rotation of the c01- lar and carrying means engageable with the last vmentioned gear when moved toward it, and

brake mechanism operable to releasably; hold the spider against rotation with the body wherejby when the clutch means are engaged the last sleeve to rotate" `with respect to the body. i

6. A boring `tool of theclass described comprising a hollow'fcylindrical body adapted to surround and for securement upon a boring bar, a

slide movable 'radiallyof the body adjacent one end thereof, cutter holding means and camming means carried by the slide, a block slidable longitudinally of the body having camming means Ycooperative with thosey on the slide, a sleeve rotatable about the body, means cooperative with ""the sleeve `for translating the block on rotation of the sleeve to thereby move the slide through coaction of said camming means, and means for automatically rotating the sleeve relatively to the body when the bar is rotating to thereby progressively move the slide comprising a spider normally rotatable on the body, a pair of coaxial pinions carried by and rotatable as a unit relatively to the spider, one of said pinions having a fewer number of teeth than the other, a gear xed to the body meshing with one of said pinions, a gear rotatable relatively to the body meshing with the other pinion, clutch means disengageably connecting said gear with the sleeve, and brake mechanism operable to releasably hold the spider against rotation with the body whereby when the clutch means are engaged the last mentioned gear is driven by the pinion meshing .;therewith atl asdilerenterateefromfthat, atlwhich vr,the.1b,ody is.: :beingrtunnedntherebyto .cau-se, the 1 ;s..s1eeve.y to ylrotai'leswith respect;- toa. the f.b,Qdy;;. L said ,nzzrmechanisrn including', ay/brake ringrsurrounding .:the: body, a.z shoegrmovable. :ein` :.the brake. ring..

..;-;adapted to .be pressed against .t'.-he;spicler,v4 means nsfor releasably illiiasingfthe,` shoe against the brake ..r.f.ring, rand. means .for .holding..said:.-biasing means nlagainst'rotation with. the body:.,of the-tool.

n.7.; Aeboring head ofltherclass` clescrbedicomgfyg` 10 drivethe;sleevefrom.andrrelativelyto the-@body -evprising ahollovv cylindrical bodyradaptedtosurround and for securement upon. afeboringflbar, a rslidef-movable: radiallyE of, the body. adjacent one arend; thereof ,f cutter Y holding ,means .and y.camming i when ,the platter. is ..rotatingf with4 f. the-bane :said l means ...comprising .Ea-gear. carriedgby, the: body, a mgear. on.y the,` sleeveaandalpair cfg:pinionserespectively., meshing:Y with .1; .said y .gears ..and lentmrrtally means;l carried -by ethe... slide,. alfblock slidable 15 Arotatable as a, unit.

longitudinally of the kbody .having `cammingv ymeans ,cooperativewith thoseyonnvthe slide, a sleeve rotatable about-.thetbodyr means .cooperay {f-tive withthe .sleeve xfortranslating., the block on rrcrotationfof the sleeve to.- thereby movetheI slidequ .v athrough; coaction of saidlcamming means, .antf

--nmeansor automaticallyAv rotating the. sleeve ,s relatively-.to the .-body when, the bar is rotating to i Inthereby;.progressively move the. s1ide comprising 1,1; aigspider normally rotatableronrthe.body, a...pairz5,

ofacoaXal .pinions carried by landlrotatable, as a @.runitzrelatively to. thel spider.-1one ,of said pinions having, a-fewennumber .ofeteeth thanthe other, .1. agear 'fixedfto.theabody:.rneshingawith one, of

l.\.fsaid-, pinions, afl-gear. f rotatable relatively .to the5 9.=,Al self-contained .boring heade'alaptedto: be ....1s1id1 longitudinally` over, the. :endeofwandf falong a fmboringnbar rto afpredeterminel position-thereon :rand comprising a.: hollowI :generallyefeylindrical body-affording'. .an uninterrupted:.pas-sageeeforfre- .rceiuing. the bar, means t operable. sto, removably securerthe bodytorthebar. in .saiglapositiom afU- .f f shaped slide having` spaced legs .embracing thebar f; Whentheheadis seated thereon, theislideihavfing limited radial.;` .movement with respect ,to the body and adapted to support a cutter .adjacent its Awouter.fend,A a ,sleeve rotatable; aboutathe tbody, means, interposed between.. .A the. ,sleeve l the s slide for .moving the glatter. .on rotation,.,.of,.the ,30 f.s1ee.ve,;. .and e-means normally operative ..to.:;drive .the sleeve from. and relativelyto thebodywhen .;,f:the,..latter. is rotating; With. the. barato thereby n.movefthefslide, said'gmeans fincludingzgearshrespectively carried by the-body. .-andsleeve Land a the. ,body-whereby.. when.the,clutchmeans ar snypalmof, Ipinions respectively .meshingawithhsaid fr; engaged .the .last mentioned gearf is drivenfby: the ..\-;pinion. meshing therewith.; at.. a different mate 1;,-froinftl'1atl at 'Whichathe bQdyis.-being -.turned f thereby to. cause ,thef sleeveA to-rotate 4withrespect ring surrounding the spider, ashoe loosely.y seatng ini the ring vhavingits inner. :feces: conform- .f l Lng;- to thespiderp meansA rior.. forcing esaid. shoe against the. spider .to restrain:it..,irom .rotation ",the- .brakering; al .collan `szurroundingnrl'fhe bar I1-andi bearingY Lon the rbrake ring a sleeve-zon-fthe bar, means. tfor. 'f fore-ing1 the. sleeve,... tdwardrthe i-z-'shoegv and a `spring..interpesed --loetitleen thershoe n the; spring; car1:..be,.\compressedVA tof-force. the .shoe ovvardv g thespiderg.. the bari .beingnadapted for anchorageagainst a- Xedr support .to.-.prevent., its r .i f rotation; in ones,directon.

wslid longitudinally over .the endofand.. along a i5,- boring-barl to a predetermined; position lthereon and` comprising a hollovv.-I 4generally cylindrical .landco'llarWhereby-through-rotationofthe sleevea` 56 m4553540 Ruhland mu1yM1891 .-.;.flgears,f and means1 normallynmaintainng., driving v-;lcormectiorrfbetvveenxthe pinionsv wherebytoeause f, lthem nto.y rotate. as a. .unity ibut. adaptedto. :sever wsuch connectiont when the islidereaehes .thelmit tofthefbody-fsaid*mechanism wmprisi-r1ebrakeV 40-,ot.v.itsradia1-trave1 manexeeSsive,ioadisthmwn ,.1 1on .the lecutter.

WILLIAM *.PENN-GASKELL HALL :REFERENCESQCITED l Chandler rrrAugel22t1944 

